It is well known to those of ordinary skill in the art that compressible and incompressible fluids, such as gases and liquids, surfaces, and materials in general, can be treated with photons in the ultraviolet (UV) segment of the electromagnetic radiation spectrum. Such irradiation may also include combinations other photons in the visible (Vis) and infrared (IR) segments of the electromagnetic spectrum, whose emission can be spontaneously occurring or engineered. Treatment via irradiation with UV photons and/or combinations with Vis-IR photons has multiple goals, and following a few of them are listed: 1) polymerization of chemical compounds, 2) optical excitation, 3) oxidation of species in the presence of a photo-catalyst, 4) decomposition of organic and inorganic compounds, and 5) neutralization of unicellular and multicellular organisms to inhibit their reproduction and so decrease their concentration.
Spontaneous, stimulated, and/or engineered emission of UV radiation has been traditionally provided with a variety of discharge-based sources. Currently, mercury (Hg) vapor lamps play a dominant role as common discharge-based sources because phosphors can be integrated within their structure to emit visible electromagnetic radiation (light) for general lighting applications. For instance, compact fluorescent lamps (CFLs) though being phased out because of concerns linked to Hg pollution and disposal, are found in light fixtures around the world. When used without phosphors, Hg vapor lamps emit electromagnetic radiation in the UV-A, UV-B, and/or UV-C range; therefore—as part of a long-established custom since 1920's, these sources have been used for germicidal applications, and more recently for oxidation, curing, and general treatment purposes.
For the correct functionality of an Hg vapor lamp, it is required that Hg is first vaporized and then ionized; UV photons are not emitted if this sequence is not completed. Warm-up times are therefore required, and during these times a given Hg vapor lamp will not provide an adequate UV irradiation level. There are three main categories of Hg vapor lamps: low pressure (LP), medium pressure (MP), or doped high pressure (HP). An ordinary LP Hg vapor lamp is characterized by relatively broader spectral emission centered at ˜254 nm, while a HP Hg vapor lamp exhibits a larger relative spectral emission centered at ˜365 nm. Independently of their classification, every kind of Hg vapor lamp exhibits a large distribution of smaller relative electromagnetic spectral emissions that span 185 nm to nearly 600 nm. While the spectral energy distribution of Hg mercury lamps can vary greatly from manufacturer to manufacturer, and from one kind of Hg vapor lamp to another, the energy spectral distribution is fixed for a given Hg vapor lamp. This implies that the single spectral emissions cannot be engineered to be enabled or disabled, red shift or blue shift; similarly, and most importantly the polarization of the emitted photons cannot be controlled either.
A less common kind of high pressure gas discharge is the excimer lamp, whose relatively narrower energy spectral emission (10 to 20 nm) is centered around a fixed wavelength in the range 126 to 352 nm; is broad (10 to 20 nm) and centered around a fixed wavelength in the range 126 to 351 nm. Similarly to other gas discharge lamps, the spectral emission of excimer lamps cannot be engineered to enable or disable desired wavelengths, red or blue shift, and control the polarization of the emitted photons.
Recent progress in excimer lamp technology has enabled microplasma UV sources, which have a much reduced foot print, in some cases comparable to solid state UV sources. Inside a microplasma UV source, stimulated xenon gas confined in microcavities produces UV radiation centered at 173 nm. Phosphors can be used to convert this wavelength in the UV-A, UV-B, or UV-C region of the electromagnetic spectrum including areas of interest in the range 173-220 nm, and at around the germicidal wavelength (260 nm). Microplasma UV sources are of significant commercial interest because their reduced footprint allows application where size constraint have prevented the use of conventional Hg vapor sources. However, similarly to other gas discharge lamps, the polarization of the emitted photons is not engineered.
Hg vapor or excimer lamps are characterized by a form factor, which is inflexible. Additionally, they typically require high power and high voltages; thus, they must use line voltage, and must be addressed as separate components that are not arbitrarily scalable. Because of the inflexible form factor of the Hg vapor, or excimer lamps, the architecture of the system that uses them is constrained. In a disinfection system for fluids, the typically tubular or linear Hg vapor or excimer lamps emit photons that pass through the fluid to be disinfected and are absorbed by another surface, or at best reflected once of twice before they are lost. This translates into a very inefficient use of photons, and a continuous need to generate and replace them. This also creates a scenario where there the radiation field is not uniform. In order compensate for losses and non-uniform radiation fields, increasingly high intensity Hg vapor or excimer lamps must be used.
During the last two decades, solid state sources, such as light emitting diodes (LEDs) and Laser Diodes (LDs) have been engineered to emit UV radiation when a current in applied to them. UV LEDs and LDs are of great commercial interest. Because of their reduced footprint (typically 0.2 mm2 to 1 mm2) they can enable commercial applications in disinfection, advanced oxidation, curing, polymerization, optical excitation where architecture constraints have impeded the use of conventional use Hg vapor lamps and excimer Lamps.
Most of the solid state sources, such as light emitting diodes (LEDs) and Laser Diodes (LDs) generate UV radiation by recombining electrically charged carriers (electrons and holes) in the active region of a heterostructure typically made of an III-nitride semiconductor alloy that incorporates specific percentages of aluminum, gallium, and nitrogen.    Ternary III-Nitride AlloyAlxGa(1-x)Nwhere “Al”, “Ga”, and “N” are the atomic symbols of elemental aluminum, gallium, and nitrogen, respectively; “x” is percent value. In this alloy the percent aluminum does not only determine the chemical composition but also the bandgap of the alloy, and the wavelength of the emitted photon.    Photon Wavelength, λ (nm)
  λ  =            1      ,      240              E      g      where “ Eg” is the bandgap energy expressed in electronvolt(eV). Based on peer-reviewed literature based values, for an alloy made of 100% aluminum, the bandgap value is 6.2 eV, and 3.4 eV for an alloy containing 0% aluminum, which respectively yields emission of photons with a wavelength of 200 nm, and 365 nm, respectively. By varying the percent of Aluminum between 0% and 100%, solid-state devices such as LEDs can be engineered to generate emission of UV-A, UV-B, and UV-C radiation. While the photon emission can be engineered, the polarization of the emitted photons is not engineered.
Solid-state sources such as UV LEDs and UV LDs, and microplasma UV sources, are used to perform the same functions as Hg vapor lamps. In addition they are environmentally friendly because of the absence of Hg; however, differently from Hg vapor lamps, they enable zero-emission limitations because their on-off operation and their UV emission is pseudo-instantaneous and limited to only a few nanoseconds when supported by adequate electronic drivers.
The use of UV LEDs, UV LDs, and microplasma UV sources are poised for explosive growth because of growing needs to treat compressible and non-compressible fluid, materials, and surfaces and shield general population for the increasing public health threat of drug resistant waterborne and airborne pathogens. The use UV LEDs, UV LDs, and microplasma UV sources will be facilitated by their reduced foot-print, which allows integration in portable devices, and also applications where size constraint is critical, such as small pipes or small surfaces.
UV sources have been historically used for their germicidal effect as early 1920. It is well known to those of ordinary skill in the art that UV radiation can be used to damage the nucleic acids contained within the structure of a unicellular or multicellular organism. Direct and often irreparable damage to the nucleic acids (DNA and RNA) can occur when exposed to UV radiation, and most effectively with UV-C radiation. With damaged nucleic acids, unicellular and multicellular organisms are unable to reproduce, and so they cannot form colonies.
Although it is well known to those of ordinary skill in the art that both DNA and RNA have a board absorption curve spanning from 200 nm to 400 nm; however, they also exhibit and relative, yet moderate maxima peak absorption centered at 260 nm, with the majority of UV absorption occurring between 240 nm and 280 nm. LP and MP Hg vapor lamps have emission peaks at 253.7 nm, with MP Hg vapor lamps having additional secondary and narrow emissions across the peak microbiocidal region of nucleic acids. Similarly, excimer lamps have a quasi-monochromatic emission centered at either 248 nm or 282 nm. Microplasma UV sources can be tuned with phosphors to generate quasi-monochromatic emission centered at 265 nm. UV LEDs, and UV LDs can be tuned to emit a broad emission (10-15 nm Full Width Half Maximum) centered at desired germicidal wavelength, and most commercial devices generate an emission centered anywhere from 255 nm to 285 nm.
Germicidal efforts have naturally targeted 260 nm presuming that maximum damage to nucleic acids would occur in conjunction with maximum optical absorption. This practice has been adopted for decades, and it has lead to a commonly accepted strategy that suggests to use a fixed-wavelength UV radiation to achieve disinfection for any possible microorganism, and provide an exposure to radiation measured in mJ per unit area that has been experimentally, and often empirically determined to neutralize the a desired microorganism. A similar strategy has been accepted for advanced oxidation, photolysis, and photocatalysis, and general irradiation treatment. Thus instead of engineering the wavelength emission of a UV source to target the exact wavelength absorbed by a given contaminant or photocatalyst, and achieve optimal efficiency, UV lamps with fixed emission spectra are matched as closely as possible to target absorption bands, often very inefficiently, to achieve an acceptable effect by means of a “brute force” approach.
A similar method has been used for Advanced Oxidation Processes (AOPs), which have started receiving adequate attention since the late 1980's for application in water treatment. AOPs define a set of procedures mainly designed to removed organic materials in water and wastewater by means of a chemical reaction (oxidation) with hydroxyl radicals (·H) produced by photocatalysis of water molecules in the presence of a photocatalyst (TiO2, NiO2) and UV photons. Recently, the terms AOP has been used to refer so a specific set of chemical processes that use “consumables” such as hydrogen peroxide (H2O2). Following are the most common mechanisms of ·OH production used by AOPs:    Oxidation With Photocatalyst (TiO2)
UV photons absorbed by the surface of TiO2 generates a free electron-hole pair e−, h+. Water is adsorbed into the TiO2 surface, reacts with holes (h+), and ·OH radicals are produced.TiO2+UV→e−+h+Ti(IV)+H2OTi(IV)—H2OTi(IV)—H2O+h+Ti(IV)—·OH+H+    Homolytic Bond Cleavage of Hydrogen Peroxide (H2O2):
UV photons cleave O—O bond of H2O2 and generated formation of ·OH.H2O2+UV→2·OH
AOPs are applicable in many scenarios where a variety of organic contaminants must be neutralized at the same time. However the “brute force” approach to provide a fixed-wavelength UV radiation has affected the development of AOPs with non-negligible drawbacks. UV sources with fixed emission spectra are matched as closely as possible to target absorption centers and often optimization is sacrificed for convenience. For instance, in natural water H2O2 competes for UV photons with the background matrix, and especially with dissolved organic matter in the 240-300 nm range. Since H2O2 has a very broad UV absorption, most systems use massive 365 nm sources (relatively inexpensive) to achieve a nearly %1 homolytic cleavage of H2O2. In this case, “conveniently inexpensive” 365 nm photons are used large quantity to achieve a sufficient ·OH concentration from a yielding method that is 99% inefficient. The un-cleaved H2O2 must be neutralized by other means that cause increasing system cost.
Additionally, the transmission of UV photons is also affected by the transparency of the medium, a phenomenon that is generally described by the Beer-Lambert Law. According to this known law, the attenuation of radiation traveling through a medium is related to the properties of the medium itself, and also directly proportional to the concentration(s) of the attenuating species. such as particles, pollutants, and compounds that are present in the medium.    Beer-Lambert Law
  T  =                    ϕ        e        t                    ϕ        e        i              =                  e                  -          τ                    =              10                  -          A                    where “T” is the Transmittance of the medium, Φe† is the radiant flux transmitted through the medium, Φei is the radiant flux received by the medium, τ is the optical depth of the medium, A is the absorbance of the medium.    N Attenuating Species in the Medium
  T  =            e                        -                                    ∑                              i                =                1                            N                        ⁢                                                  ⁢                                          σ                1                            ⁢                                                ∫                  0                  l                                ⁢                                                                            n                      i                                        ⁡                                          (                      z                      )                                                        ⁢                  dz                                                                    ⁢                                        =          10              -                              ∑                          i              =              1                        N                    ⁢                                          ⁢                                    ξ              1                        ⁢                                          ∫                0                l                            ⁢                                                                    c                    i                                    ⁡                                      (                    z                    )                                                  ⁢                dz                                                        where “σ” is the attenuation cross section of the attenuating species “i” in the medium, “ni” is the number density of the attenuating species “i” in the medium, “ξi” in the absorptivity of the attenuating species “i” in the medium, “ci” in the amount concentration of the attenuating species “i” in the medium, and “l” is the path length of the radiation through the medium.
Another naturally occurring phenomenon that hinders the treatment of compressible and non-compressible fluids, surfaces and materials with UV photons is the Rayleigh scattering, which is the dominant elastic scattering of electromagnetics radiation by particles of organic and inorganic material, unicellular and multicellular organisms that are at least 10× smaller than the wavelength of the radiation. This phenomenon can occurs when electromagnetic radiation travels trough solids, liquids, and gases that are transparent to the radiation itself. This phenomenon is caused by the electric polarizability of matter organized into a “particle” much smaller than the irradiating wavelength. The oscillating electric field of an electromagnetic wave acts on the charges within the “particle” causing them to resonate with a similar frequency. In this case the “particle” turns into a radiating dipole that scatters electromagnetic radiation.
Several impediments that stem from the Beer-Lambert Law, and the Rayleigh scattering seriously hinder the use of UV radiation for treatment of fluids, and especially water. In water with a transparency level of 70% to germicidal range UV radiation, the attenuation of the radiation is so severe to require significant exposure times, and amounts of energy per unit area often so exceptionally large that they cannot be provided by UV sources. Thus this requires filtering the water and further processing to increase its level of transparency. This is especially hindering for high purity, or drinking water processing industries, and water municipality, which deal with vast amounts of water that needs to be processed and treated rapidly. The Rayleigh scattering allows small unicellular and multicellular microorganism to scatter UV radiation, resisting its damaging effects. The presence of certain viruses in water hence requires irradiation with exceptionally large amounts of UV radiation.
There is a plethora of unicellular organisms such as archaea, protozoa, bacteria, viruses, molds, and spores that can be easily differentiated from one another, and categorized. However, this does not mean that all microorganisms in the same category are created equal. Experimentally determined UV rate constants reported in the literature indicate that some microorganisms are more resistant to UV irradiation than other microorganisms. In fact, there are several factors that determine the level of resistance of a microorganism to UV irradiation. Some of these factors have been addressed with novel technologies (Table 1), while others have not yet been addressed with targeted technology. (Table 2).
TABLE 1Factors in Microorganism UV ResistanceAddressed with TechnologyDoubleDouble stranded DNA is less affected by UV damagestrandedbecause it can be repaired or photo reactivated.vs. singleSolid-state optoelectronics, mercury-gas discharge,strandedmicro-plasma technology provide sources that can beDNAengineered to emit combinations of narrow, or quasi-narrow UV emissions that abate the effects of photoreactivation and photo repair. For instance, Mediumpressure mercury-gas discharge (MP) UV lamps havebeen reported to have an advantage over thecounterpart low-pressure (LP) UV lamps for disinfectionof bacteria in water in terms of photo reactivation. Inaddition to nucleic acid damage, the polychromaticoutput of MP UV lamps also allows protein degradationand enzymatic breakdown, which is associated with ahigher level of inactivation of microorganisms withrespect to the same microorganisms treated with anequivalent dose of radiation from LP UV lamps.LengthShorter DNA strands are more susceptible to significantof DNAUV damage compared to longer DNA strands; theStrandquantum inactivation yield is indirectly proportional toits molecular weight.Industrial MP UV lamp based systems can providesignificantly high doses of germicidal radiation (oneorder of magnitude larger than counter part LP UV lampbased systems). This allows a “brute force approach”that reduces the importance of the length of DNA strandas a variable.High CGCytosine binds specifically to Guanine with a tripleContenthydrogen bonding (CG), which is energetically morestable that the double hydrogen bonding that bindsAdenine with Thymine (AT). Nucleic acid strands with ahigh content of CG are more resistant to UV induceddamage.Solid-state optoelectronic technology (Light EmittingDiodes, and Laser Diodes) provide sources that that canbe engineered to emit narrow and/or quasi-narrow UVemissions that specifically target the peak opticalabsorption of AT as a method to induce targeted damageto a nucleic acid strand.
TABLE 2Factors in Microorganism UV ResistanceNot Addressed by TechnologyUV PhotonOnly a very small fraction of UV photons cause UVStatisticaldamage because 1) UV photons must be first absorbedAbsorption(Grotthus-Draper) before a photochemical reaction cantake place, and 2) even if a UV photon is absorbanceoccurs, a photochemical reaction may not necessarilytakes place (Stark-Einstein).MicroorganismMicroorganisms << 10X smaller than the wavelength thatSizeirradiates them will cause Rayleigh scattering. Thus,microorganisms with a diameter of 20 to 30 nm wouldonly partially inhibit the Rayleigh effect forgermicidal wavelengths (254 to 280 nm).ShieldingCapsid protein, lipids, or other packaged viral proteinsand/orcan shield DNA from UV photons. Similarly UV photonsInner Filtercan be absorbed by various absorption centers beforeEffectthey can hit the nucleic acid and have chance to beabsorbed and induce nucleotide dimerization.
It is well known to those of ordinary skill in the art that the field of physics offers different definitions of electromagnetics radiation.
In classical electrodynamics, electromagnetic radiation is defined with the concept of electromagnetic waves, which are a oscillations of electric and magnetic fields, synchronized and perpendicular to each other and perpendicular to the direction of the wave propagation, forming a transverse wave. In other words, if the direction of the wave propagation in the x-direction in the x-plane of a 3D Cartesian axis system, then the oscillations of the electric and magnetic fields occur in the y-z plane.
In quantum theory of electromagnetism, electromagnetic waves consist of elementary, massless particles called photons, which are responsible for all electromagnetic interaction. Energy is carried by photons, and the energy of each single photon is quantized and expressed by Planck's equation.    Planck's EquationE=hvwhere “h” is Planck's Constant, and “v” is the frequency of the photon.
The wavelength of the photon generated in the active region of a semiconductor-based heterostructure can be linked to Plank's equation.    Photon Wavelength, λ (nm) and Planck's Equation
  E  =      hv    =                            h          ⁢                      c            λ                          ∴                  λ          ⁡                      (            nm            )                              =                        h          ⁢                      c            E                          =                                                            (                                  4.136                  ×                                      10                                          -                      15                                                        ⁢                                                                          ⁢                  eV                  ⁢                                                                          ⁢                  s                                )                            ⁢                              (                                  2.998                  ×                                      10                    8                                    ⁢                                                                          ⁢                  m                  ⁢                                                                          ⁢                                      s                                          -                      1                                                                      )                                      E                    =                                    1              ,              240                                      E              g                                          where “Eg” is the bandgap energy of the active region of a semiconductor-based heterostructure of the expressed in electronvolt(eV).
It is well known to those of ordinary skills that electromagnetic radiation carries energy. Nonetheless, it is less widely known that electromagnetic radiation also carries momentum, which is a characteristics property of an object in translational motion, or more precisely the movement that changes the physical position of an object, as opposed to rotational motion. Most can relate to the Newtonian definition of momentum as the product of the mass of the velocity of an object in translational motion, which is less intuitive when applied photons as massless particles; nonetheless, practical evidence that electromagnetic radiation carries momentum is found in the physical phenomenon known as “radiation pressure”, in which a flux of photons transfer their momentum to an absorbing or scattering object and exert pressure on it.
The magnitude of the pressure exerted on a body by radiation, when the momentum carried by the former is transferred by the radiation, is relatively speaking small and therefore difficult to be observed by human beings without the aid of instrumentation. But it the overall scheme of things, radiation pressure can have non-negligible effects. If the pressure exerted by radiation emanated by the Sun in our solar system were not considered (determined to be 1,361 Wm−2 at 1 AU, i.e. the distance from the Sun to Earth.), the trajectory of spacecraft in our solar system would have been affected with significant theoretical vs. experimental deviations.
Experimental proof that electromagnetic radiation carries momentum was obtain during the years 1901-1903 by Russian physicist Pyotr Lebedev, and American physicists Earnest Fox Nichols and Gordon Ferrie Hull, following the assertion that electromagnetic radiation carries momentum published by Scottish scientist James Clerk Maxwell in 1865. However, it was the German astronomer Johannes Kepler that first reported in 1619, that the tail of a comet always points away from Sun, intuiting that sunlight was exerting some force on the comet tail.
The concept that electromagnetic radiation carries momentum is very important because the implication is that momentum is a conserved quantity. In other words, the momentum carried by electromagnetic radiation remains unchanged until acted upon by an external system, or transferred or absorbed by another body, or matter in general. The exchange of momentum with matter is a phenomenon that is not widely known. Thought is has been exploited to generate optical tweezers, the interaction of momentum carried by UV photons with matter is not widely known because both UV photon sources and UV compatible materials have been historically scarce.
As it travels in space, electromagnetic radiation can also rotate around its own axis of propagation. This rotation can assume two distinct forms, which are associated with two distinct forms of angular moment.
One form of rotation is characterized by the circular polarization of the electromagnetic magnetic wave, which occurs when the electric field vector rotates at a constant rate around the propagation axis (circular polarization). A circularly polarized electromagnetic wave can be in one of two possible states, namely right or left circular polarization. From quantum physics point of view, the circular polarization is linked to the spin of a phonon, which too can be found in one of two possible states, namely right or left spin.
The other known form of rotation is characterized by the shape of the wavefront, which is the distribution is space of propagation points (surface) characterized by the same phase.
The form or rotation involving the electric field vector of an electromagnetic wave (or photon spin) is associated with a kind of angular momentum known as Spin Angular Momentum (SAM); the form or rotation involving the shape of the wavefront is associated with a kind of angular momentum known as Orbital Angular Momentum (OAM).
Spin Angular Momentum (SAM) is associated with the circular polarization of the electromagnetic magnetic wave, which occurs when the electric field vector rotates at a constant rate around the propagation axis. Depending on the field rotation and the commonly accepted conventions, the circular polarization can be “left” or “right” as illustrated. From a quantum physics point of view, electromagnetic radiation carries SAM when photons carry a spin angular momentum of ±h, where h is the reduced Plank constant, and the + is the sign associated with left circular polarization, and the − is the sign associated with right circular polarization. In other words the circular polarization is linked to the spin of a phonon, which too can be found in one of two possible states, namely right or left spin.
Orbital Angular Momentum (OAM) is associated on the field spatial distribution of the electric field, not with its polarization. It is categorized as external or internal OAM. The external OAM is origin dependent angular momentum that results from the cross product of special location of the center of the beam of electromagnetic wave and it total linear momentum. The internal OAM is associated with an origin-independent angular moment with a helical mode. Helical modes of electromagnetic fields are characterized by wavefront that is shaped like a helix, with an optical vortex at the center of the electromagnetic radiation beam. In this case of non-cylindrical symmetry wave propagating along the z-axis, the OAM can be expressed asLz=mℏwhere ℏ is the reduced Plank constant, and m is an integer called the topological charge. If m≥2 then the wavefront is composed of |m| distinct yet intertwined helixes with step length equal to |m|λ, where λ is the wavelength of the electromagnetic radiation wave, and direction determined by the sign of |m|. If m=1, then the wavefront is composed by a single helical surface with step length equal to λ. If m=0, then mode if not helical, and wavefront is composed by a simple flat surface.
It is less commonly known that angular momentum carried by electromagnetic radiation can be transferred on to matter. When electromagnetic radiation carrying a non-zero angular momentum (SAM or OAM) impinges on the axis of an absorbing particle, the particle will absorb the angular momentum; this causes the absorbing particle to acquire a rotational motion. If the absorbing particle is impinged off-axis by different photons carrying different angular momenta, then the particle will be subjected to a combination of different rotational motions. SAM will induce rotational motion around the axis of an absorbing particle (particle spinning). OAM will induce a revolution of the absorbing particle around the OAM axis of the electromagnetic radiation; the form or rotation involving the shape of the wavefront is associated with a kind of angular momentum known as Orbital Angular Momentum (OAM).
Circular polarization of electromagnetic radiation, which carries spin angular momentum (SAM) is commonly achieved by means of quarter wave plates, which are planar devices made of birefringent materials. These birefringent materials are crystalline materials that exhibit an index of refraction dependent of the crystallographic direction. Birefringent materials are characterized by two possible optical paths corresponding to two different indexes of refraction, which basically describe the speed of propagation of electromagnetic radiation in a given medium. Within a birefringent material, electromagnetic radiation can propagate with two distinct possible speeds depending on the direction of electromagnetic radiation. A quarter wave plate is designed so that electromagnetic radiation propagating in the direction with the larger index of refraction is retarded by 90° in phase with respect to the phase of the electromagnetic radiation propagating in the direction with the smaller index of refraction.
There are several methods to generate orbital angular momentum (OAM), including holograms (pitch-fork, fork-like, or computer generated spatial light modulators), Q-plates, Cylindrical Mode Converters, and dielectric metasurfaces.
Holograms include design algorithms for obtaining super-resolution with coherent, incoherent, or a mixture of coherent or incoherent radiation near-UV and/or UV radiation.
Traditionally, super-resolution is achieved with lenses, which are designed numerically by modifying a pattern of concentric rings until the target design is obtained. Though this approach can potentially be extended to incorporate additional design criteria, it does usually not allow one to design a specified trade-off between resolution and power efficiency, nor the location of the undesired side lobes in the super-resolving focal plane.
There exist design algorithms for obtaining super-resolution with coherent, incoherent, or a mixture of coherent or incoherent radiation near-UV and/or UV radiation.
The Prior Discrete Fourier Transformation (PDFT) algorithm is an example of design algorithm for obtaining super-resolution with coherent near-UV and/or UV radiation.
The PDFT algorithm was originally conceived as a super-resolution imaging technique. The mechanism of the PDFT algorithm may be summarized as follows. At a finite set of arbitrary points, the signal value is expressed as the superposition of a set of linear independent functions, which express prior knowledge we have about the signal synthesis problem. For super-resolution filters this may be the bandwidth of the signal and the functions are shifted Sinc functions. The solution of the PDFT provides the minimum norm transmission function compatible with the specified signal values.
Generally, the PDFT solution will be real valued or complex valued and an addition-encoding step is necessary to turn the PDFT solution into the phase-only transmission function of a standard diffractive optical element.
Nonlinear design algorithms have also been used to design super-resolution filters. These algorithms optimize the zone width of domains of constant phase inside the DOE aperture, either matching a finite set of signal samples, or optimizing additional components of a more complex cost function.
More recently, super-resolution elements were demonstrated based on the concept of super-oscillations. The design mechanism is very similar to the PDFT, but done in the z-transform domain, which unnecessarily limits the specified signal points to zero crossings of the output spot.
What is still needed in the art, however, is a system that can that generate UV photons with engineered SAM, OAM, and/or a combination of both to achieve optimized angular momentum transfer onto matter (nucleic acids, protein, photoinitiators, photosensitizers to cite a few), and to treat organic and inorganic substances and/or impurities, including biological materials, unicellular organisms such as archaea, protozoa, bacteria, viruses, molds, spores, cysts, and multicellular organisms, such as most fungi, and algae.